Image Upload into S3 (CodeIgniter)

gistfile1.txt

    /**
     * File Upload into Amazon S3
     * @param string $input_name
     * @param int $restaurant_id
     * @return string/bolean
     */
    public function _fileUpload($input_name, $restaurant_id) {

        if (isset($_FILES[$input_name]) && ($_FILES[$input_name]) != NULL) {

            $file_full_name = $_FILES[$input_name]['name'];
            // current time and date 
            $extention = explode(".", $file_full_name);
            //$picname = $filename[0];
            //$file_type = $filename[1];
            $file_type = strtolower(end($extention));

            $rand_string = random_string('alnum', 8);

            // AMAZON
            $file_new_name = date("YmdHis") . $restaurant_id . $rand_string . "." . $file_type;

            // AWS Start
            require_once './aws/aws-autoloader.php';

            // Instantiate an Amazon S3 client.
            $s3 = new Aws\S3\S3Client([
                'version' => 'latest',
                'region' => 'ap-southeast-1',
                'credentials' => [
                    'key' => 'YOUR_KEY',
                    'secret' => 'YOUR_SECRET',
                ],
            ]);

            try {
                $result = $s3->putObject([
                    'Bucket' => 'BUCKET_NAME',
                    'Key' => 'UPLOAD_DIR' . date("Y") . '/' . date("m") . '/' . $file_new_name,
                    'Body' => fopen($_FILES[$input_name]['tmp_name'], 'r'), //'Body'   => fopen('/path/to/file', 'r'),
                    'ACL' => 'public-read'
                ]);
            } catch (Aws\Exception\S3Exception $e) {
                echo "There was an error uploading the file.\n";
            }

            if ($result['ObjectURL']) {
                return $file_new_name;
            } else {
                return NULL;
            }
        }
    }